Travel storage issue

That's my take on things. Cards are small and cheap and reliable, and if you are not a pro requiring instant secure backup, or anyone requiring on-site editing, why bother with anything else. I do not delete on the go. Full card stays full. I still use class 6 cards as backups, particularly if shooting without using burst mode, or shooting on the world's slowest filewriting camera (Sigma DP2M - gorgeous images, but gaaah, could get grey hair while the thing writes).